Do you think that the man in this photo is a real scientist? In science fiction, scientists may be portrayed as wild-eyed and zany, randomly mixing chemicals in a lab. But that portrayal couldn’t be farther from the truth. Real scientists are disciplined professionals, and scientific investigations are very organized and methodical.

Investigations in Science

Investigations are at the heart of science. They are how scientists add to scientific knowledge and gain a better understanding of the world. Scientific investigations produce evidence that helps answer questions. Even if the evidence cannot provide answers, it may still be useful. It may lead to new questions for investigation. As more knowledge is discovered, science advances.

Scientists investigate the world in many ways. In different fields of science, researchers may use different methods and be guided by different theories and questions. However, most scientists follow the general steps outlined in the
Figure
below
. This approach is sometimes called the scientific method. Keep in mind that the scientific method is a general approach and not a strict sequence of steps. For example, scientists may follow the steps in a different order. Or they may skip or repeat some of the steps.

A simple example will help you understand how the scientific method works. While Cody (
Figure
below
) eats a bowl of cereal, he reads the ingredients list on the cereal box. He notices that the cereal contains iron. Cody is studying magnets in school and knows that magnets attract objects that contain iron. He wonders whether there is enough iron in a flake of the cereal for it to be attracted by a strong magnet. He thinks that the iron content is probably too low for this to happen, even if he uses a strong magnet.

Cody makes an observation that raises a question. Curiosity about observations is how most scientific investigations begin.

A:
Cody’s question would be, “Is there enough iron in a flake of cereal for it to be attracted by a strong magnet?” His hypothesis would be, “The iron content of a flake of cereal is too low for it to be attracted by a strong magnet.”

Cody decides to do an experiment to test his hypothesis. He gets a strong magnet from his mom’s toolbox and places a dry flake of cereal on the table. Then he slowly moves the magnet closer to the flake. To his surprise, when the magnet gets very close to the flake, the flake moves the rest of the way to the magnet.

Q:
Based on this evidence, what should Cody conclude?

A:
Cody should conclude that his hypothesis is incorrect. There is enough iron in a flake of cereal for it to be attracted by a strong magnet.

Summary

Investigations are at the heart of science. They produce evidence that helps scientists answer questions and better understand the world.

Most scientists follow the same general approach to investigation, which is called the scientific method. It includes the following steps: ask a question, do background research, construct a hypothesis, test the hypothesis by doing an experiment, analyze the data and draw a conclusion, and report the results.

Practice

Read the procedure for the “Money in a Blender” investigation at the following URL. Then answer the questions below. With your teacher’s or parent’s approval, try the activity yourself.